If you are interested in cleaning up the diagnostics, don't use par_threshold and par_report options when you want only OpenMP threading. If those options do anything without /Qparallel, their result is likely to be bogus, and I have doubts about their use with /Od as well. You wouldn't need to specify reentrancy or threadsin addition to /Qopenmp or /Qparallel. I don't have a clue what you mean by /GB. What you have quoted are only warnings, and there is an indication that your OpenMP parallel compilation has been accomplished as directed. Your warnings may be produced by the combination of invoking parallel diagnostics with your do while loop structures. OpenMP and Qparallel work better with plain old counted DO loops.